Carpets produced from synthetic or natural fibers and mixtures thereof are commonly used in residential and commercial applications as a floor covering. Various types of fibers can be used in making carpets such as polyamide and wool.
However, carpets irrespective of whether they are made from natural or synthetic fibers are all prone to soiling and staining when contacted with many household items. Foods, grease, oils, beverages such as coffee, tea and soft drinks especially those containing acidic dyes can cause unsightly, often dark stains on carpets. Also fibers may become soiled as a result of dirt particles, clay, dust, particulate soils in general, coming into contact with, and adhering to the fibers of the carpet. These latter soils often appear in the form of a diffuse layer of soils rather than in the form of spots and tend to accumulate particularly in the so called "high traffic areas" such as near doors as a result of intensive use of the carpets in such areas.
There are a number of carpet cleaning compositions described in the art for removing stains and soils. However, these compositions do not satisfactorily meet the consumer's needs as regards their cleaning performance on different types of stains and soils. Indeed, these carpet cleaner compositions are not fully satisfactory for removing particulate soils, especially in the so called "high traffic areas".
Thus the object of the present invention is to provide improved removal of particulate soils from carpets, in a manner which is applicable to a variety of carpet cleaning compositions, i.e. compositions being either in a liquid form or in a powder form or in a granular form.
It has now been found that the above object can be met by formulating compositions which comprise a chelant in combination with a soil suspending polycarboxylate or polyamine polymer. Indeed, such a composition allows to obtain excellent particulate soil removal performance especially on diffuse layers of stains and soils which occur in the so called "high traffic areas", i.e. on stains and soils which have become otherwise extremely difficult to remove. More particularly, it has been found that the use of a composition comprising a chelant, or a combination of chelants, together with a soil suspending polycarboxylate or polyamine polymer, or mixtures thereof, results in a synergistic effect on the removal of particulate soils from carpets. Furthermore, said combination of a chelant with a soil suspending polycarboxylate or polyamine polymer is particularly suitable to be used in aqueous carpet cleaning compositions which further comprise a source of active oxygen, thereby providing excellent particulate soil removal performance while delivering also good cleaning performance on other types of soils and stains like bleachable stains.
An advantage of the present invention is that it is applicable to all carpet types, especially delicate natural fibers and is also safe to all carpet dye types, particularly sensitive natural dyes used therein.
Another advantage of the present invention is that it may be applied directly on the carpet without causing damage to the carpet. In addition the cleaning action of the invention commences as soon as the carpet cleaning composition has been applied to the surface. Indeed, the use of the carpet cleaning composition of the present invention does not necessarily require rubbing or/and brushing of the carpet.
The following documents are representative of the prior art available on carpet cleaning compositions.
WO 92/17634 discloses a method for removing stains from carpet fibers which consists on applying an alkaline solution (pH=7 to 10.5) to said carpet, said solution resulting from mixing just prior use of a solution of a source of active oxygen with a solution of ammonium bicarbonate or carbonate and fluorinated alkyl sulfonic acid or its coordinated salt. This patent application nowhere mentions the use of any chelant or soil suspending polycarboxylate or polyamine polymer, let alone the benefit resulting from their combined use, in a composition for cleaning carpets, i.e. the improved particulate soil removing performance of said composition.
U.S. Pat. No. 3,607,760 discloses an aqueous carpet cleaner particularly suitable for removing pet stains, said carpet cleaner comprising hydrogen peroxide, hydrocarbon ether of ethylene or diethylene glycols, hydrocarbon monohydric alcohols and EDTA. No soil suspending polymer is disclosed.
EP-A-346 835 discloses an aqueous carpet cleaner at pH 7-12 comprising a water-soluble alcohol (C1-C5) and an oxidizing agent (hydrogen peroxide). No chelants, no soil suspending polymers are described.
European patent application 93870161.2 discloses the use of stable aqueous compositions comprising a source of active oxygen, having a pH of from 1 to 6, for the cleaning of carpets. More particularly this European patent application discloses that such compositions may further comprise from 1% to 7% by weight of the total composition of a builder system, e.g. aminopolyphosphonates. No soil suspending polymers are disclosed.